Saute onions and mushrooms in butter.
Blend in Flour and stir
Stir in Milk and Chicken Broth.
Bring to boil; once to desired consistency turn off heat.
Stir in sherry, chives and chopped chicken.
Add salt, pepper and nutmeg to taste.
Once the filling is cool, fill the crepes and chill again.
Once the crepes are chilled, preheat the oven to 350F
Bake crepes for 20 minutes.
Make the sauce:
Heat a small pan and add the butter.
Once the butter is sizzling add the flour.
Stir to make a roux.
Once the roux is desired color, add the remaining ingredients and stir.
Cook to desired consistency and then season to taste.
Pour sauce over the cooked crepes and serve.